Here the cylindrical end of one bone fits in the curved recess of another, allowing movement in one forwards, just like a door hinge. The knee and elbow are both hinge joints. The latter also allows limitedrotation of the arm bones.
Here the cylindrical end of one bone fits in the curved recess of another, allowing movement in one forwards, just like a door hinge. The knee and elbow are both hinge joints. The latter also allows limitedrotation of the arm bones.